A panel of expert advisors to the FDA has been asked to solve a mystery: What happened to thousands of women who enrolled in studies designed to evaluate rare complications that might arise years after they received silicone gel breast implants?

Ongoing Safety Studies Have Lost as Many as 79% of Enrolled Patients

FDA Questions Studies of Breast Implant Safety

Aug. 30, 2011 -- A panel of expert advisors to the FDA has been asked to solve a mystery: What happened to thousands of women who enrolled in studies designed to evaluate rare complications that might arise years after they received silicone gel breast implants?

In June, after a preliminary review of study data, the FDA concluded that breast implants were largely safe and effective but were not “lifetime devices,” citing high reoperation rates for complications like hardening of the breast and rupture of the implant.

That review also found no evidence that silicone implants were linked to rare problems like breast cancer or connective tissue diseases, concerns that have plagued the devices for decades. But the agency also noted that studies were still in progress to better answer some of those questions about rare events.

Now, however, it seems those studies have lost so many of the women they were supposed to follow that they are unlikely to offer any insight into the long-term safety of the devices.

Breast Implant Studies in Trouble

When the FDA allowed silicone gel breast implants back on the market in 2006, a condition of that approval was that companies conduct additional clinical trials to monitor complication rates and other problems that might develop over the long-term.

Some of the potential rare events that the FDA and patient advocacy groups wanted continued monitoring for included connective tissue diseases like lupus, rheumatoid arthritis, and scleroderma; nerve problems; cancer; suicide; interference with mammograms; problems in babies born to women with breast implants; and women with implants who might have had trouble getting pregnant or breastfeeding.

The companies agreed, and studies were designed that enrolled more than 82,000 women with silicone breast implants and 16,000 women with saline implants for comparison. The studies were supposed to follow the women for 10 years.

But three years into the studies, Mentor, the maker of Memory Gel implants, has lost 79% of the patients they enrolled, while Allergan, the maker of Natrelle implants, has lost nearly 40% of their study participants two years after enrollment.